﻿////////////////////////////////////////////////////////////////////////////////////
//  CameraFilterPack v2.0 - by VETASOFT 2015 //////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////

Shader "CameraFilterPack/Edge_Sigmoid" {
	Properties 
	{
		_MainTex ("Base (RGB)", 2D) = "white" {}
		_TimeX ("Time", Range(0.0, 1.0)) = 1.0
		_Distortion ("_Distortion", Range(0.0, 1.0)) = 0.3
		_ScreenResolution ("_ScreenResolution", Vector) = (0.,0.,0.,0.)
		_Gain ("_Gain", Range(1.0, 10.0)) = 3.0
	}
	SubShader 
	{
		Pass
		{
			ZTest Always
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#pragma fragmentoption ARB_precision_hint_fastest
			#pragma target 3.0
			#pragma glsl
			#include "UnityCG.cginc"
			
			
			uniform sampler2D _MainTex;
			uniform float _TimeX;
			uniform float _Distortion;
			uniform float4 _ScreenResolution;
			uniform float _Gain;
			
		       struct appdata_t
            {
                float4 vertex   : POSITION;
                float4 color    : COLOR;
                float2 texcoord : TEXCOORD0;
            };
 
            struct v2f
            {
                  half2 texcoord  : TEXCOORD0;
                  float4 vertex   : SV_POSITION;
                  fixed4 color    : COLOR;
           };   
             
  			v2f vert(appdata_t IN)
            {
                v2f OUT;
                OUT.vertex = mul(UNITY_MATRIX_MVP, IN.vertex);
                OUT.texcoord = IN.texcoord;
                OUT.color = IN.color;
                
                return OUT;
            }
#define tex2D(sampler,uvs)  tex2Dlod( sampler , float4( ( uvs ) , 0.0f , 0.0f) )
	
			float4 frag (v2f i) : COLOR
			{
				float2 uv = i.texcoord.xy;
				
				float2 p = 1.0 / _ScreenResolution.xy;
				
				fixed4 colorSum = 0.0;
				
				for(int a = -1.0 ; a <= 1.0 ; a += 1.0) {
					for(int b = -1.0 ; b <= 1.0 ; b += 1.0) {
						if(b == 0.0 && a == 0.0) colorSum += tex2D(_MainTex, uv + p * float2(b,a)) * 8.0;
						else colorSum += tex2D(_MainTex, uv + p * float2(b,a)) * -1.0;
					}
				}
				
				float3 c = colorSum.rgb;
				float avg = (c.r+c.g+c.b)/ (10- _Gain); 
				float v = (1.0 - (1.0 / (1.0 + exp( -9.0 * (avg-0.18) )))) * 2.0;
				return fixed4(v,v,v,1.0);
			}
			
			ENDCG
		}
		
	}
}